<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        div{
            width:100px;
            height:100px;
            background-color: aquamarine;
            margin:10px;
        }
        div:nth-child(2){
            /* display:block; */
            visibility:hidden;
        }
        td{
            width:100px;
            height:30px;
            border:1px solid black;
        }
        table{
            border-collapse:collapse;
            caption-side:top;
        }
    </style>
</head>
<body>
    <table cellspacing> <!--cellspacing单元格间距-->
        <caption>学生信息表</caption>
        <colgroup><!--为每一列设置颜色-->
             <col style="background-color: aquamarine;">
             <col style="background-color: blue;">
             <col style="background-color: rgb(166, 245, 20);" span="2">
             <!-- <col style="background-color: rgb(255, 196, 0);"> -->
        </colgroup>
        <tr>
            <td></td>
            <td></td>
            <td></td>
            <td></td>
        </tr>
        <tr>
            <td></td>
            <td></td>
            <td></td>
            <td></td>
        </tr>
        <tr>
            <td></td>
            <td></td>
            <td></td>
            <td></td>
        </tr>
        <tr>
            <td></td>
            <td></td>
            <td></td>
            <td></td>
        </tr>
    </table>
    <div>div1</div>
    <div>div2</div>
    <div>div3</div>
</body>
</html>